David S. Owen, Software Engineer

Project Highlights

Brought runtime of a schedule planner from astronomical to
less then 60 seconds, by using A* search with a limiting beam width, and
stopping if finding a terminal state within 10% of the heuristic's
current best guess. Also optimized the Python version to achieve another
10x speed-up.

Cut time to run a database report from over 20 minutes to under 30
seconds, simplifying the code and removing over 200 lines in the
process.

Cut session storage of a high-traffic webapp by 90% by optimizing
session-creation and use of test-cookies.

Estimated one year of a particular team's work to within 5% of
subsequent actual performance, using an estimation model and schedule
planner I developed.

Took over an existing MRI registration system; found and corrected
defects that caused rotational parameters to result in skew; implemented
MIP-mapping and other optimizations that cut runtime by 50%.

Repeatedly identified and corrected deadlock and race conditions in a
payment processor, before they became problems in production.

Developed an SQL-migrations system to version-control, coordinate,
and automate schema upgrades across multiple developers and systems.

Ported an existing image-registration and analysis system from C to
Java, developed a dynamic web front-end, and added a new optimization
algorithm for more reliable convergence.

Added multi-server, multi-head rendering to the iRun system,
selecting a much simpler TCP & threads approach over the anticipated
MPI approach; results were included in a published paper.

Identified and eliminated several difficult-to-find bugs by adding
integrity constraints to the database, sometimes adjusting the schema to
make the aspect constrainable.

Solid history of picking up struggling projects and optimizing
staffing levels, coordinating teams, and doing the work to bring them to
successful completion.

Ported several existing systems from Windows to Linux, and used free
tools (such as valgrind) to find previously unlocated and unknown
bugs.

Implemented automatic local & remote backups of key data
resources.

Created and administered several LXC & Linux-VServer containers (similar to
OpenVZ).